Important Questions and Answers on Application of IC

ic regulators

Important Questions and Answers on Application of IC Regulators

IC regulators

An integrated circuit (IC) called a voltage regulator maintains a constant fixed output voltage regardless of changes in the load or input voltage. Depending on the internal circuit topology, it can accomplish this in a variety of ways, but in order to keep this project simple, we will primarily concentrate on the linear regulator.

1. What is a voltage Regulator?

A voltage Regulator is an electronic circuit that produces a constant dc voltage regardless of changes in temperature, load current, or ac line voltage.

2. Give the Classification of voltage Regulators:

  1. Series / Linear Regulators
  2. Switching Regulators.

3. What is a linear voltage Regulator?

A power Transistor connected in series between the Unregulated dc input and the load. Is used as a series or linear Regulator, and it conducts in the linear region. The Continuous voltage drop across the series pass transistor Regulates the output voltage.

4. What is a Switching Regulator?

In order to prevent the power Transistor from Conducting current Continuously, Switching Regulators use the power Transistor as a high Frequency on/off switch. With this, Efficiency is Increased compared to series regulators.

5. What are the advantages of IC voltage Regulators?

  1.  *low cost
  2. *high reliability
  3. *reduction in size
  4. *excellent performance

6. Give some examples of Monolithic IC voltage Regulators:

78XX series fixed output, positive voltage Regulators

79XX series fixed output, negative voltage Regulators

723 general purpose Regulator.

7. What is the purpose of having input and output Capacitors in three Terminal IC Regulators?

Connecting a capacitor between the input terminal and ground eliminates the inductive effects caused by long distribution leads. The output capacitor improves the transient response.

8. Define line Regulation

Line regulation is described as the change in the output voltage expressed in millivolts. Or as a percentage of the output when the input voltage changes.

9. Define load Regulation

Load regulation describes the change in output voltage for a change in load current. Either in millivolts or as a percentage of the output voltage is specified.

10. What is meant by current Limiting?

Current limiting is the ability of a Regulator to prevent the load current from increasing above a set value.

11. Give the Drawbacks of linear Regulators:

*The input step down transformer is bulky and expensive because of low line frequency.

*Because of low line frequency, large values of filter capacitors are required to decrease the ripple.

*Efficiency suffers as a result of the transistor’s constant power loss while operating in the linear region.

12. What is the advantage of Switching Regulators?

*The power transistor is designed to function as a low impedance switch, increasing efficiency. Rather than as a constant current flow, power is transmitted across the transistor in discrete pulses.

*By using suitable switching loss reduction technique, the switching frequency can be increased so as to reduce the size and weight of the inductors and capacitors.

13. What is an Opto-coupler IC?

An opto-coupler integrated circuit contains both a photo-emitting device and a photo-sensing device (IC).

14. What are the types of Optocouplers?

  1. ·           LED and a photo diode,
  2. ·           LED and photo transistor,
  3. ·           LED and Darlington.

15. Give two examples of IC Optocouplers?

Examples for opto-coupler IC

·           MCT 2F

·           MCT 2E .

15.   Mention the advantages of Opto-couplers:

  1. *Better Isolation between the two stages.
  2. *There is no longer an Impedance issue between the stages.
  3. *Wide Frequency response.
  4. *Easily Interfaced with digital circuit.
  5. *Compact and light weight.
  6. *Problems such as noise, transients, contact bounce,.. are Eliminated.

17. What is an Isolation Amplifier?

An Isolation Amplifier is one that offers Electrical Isolation between its input and output Terminals.

18. What are the Features of Isolation Amplifier?

  1. ·           Easy to use
  2. ·           Ultra low leakage
  3. ·           18 pin DIP package

19. What is LM380?

National Semiconductor produced the power Amplifier. To an 8 ohm load, it can deliver 2.5 W minimum.

20. What are the Features of MA78s40?

  1. ·           Step up, step down or Inverting operation
  2. ·           Operation from 2.5 to 40 V.
  3. ·           80Db line

Write a comment